1. Field of the Invention
The present invention relates to a recording apparatus or more precisely, for example, to the recording apparatus on which an automatic sheet feeding apparatus may be freely fixed or unfixed.
2. Related Background Art
Recording apparatus such as printer, copying machine, facsimile etc. are so constructed that an image composed of dot pattern is recorded on the recording sheet such as paper or thin plastic sheet by driving the energy generating member of the recording head according to the transmitted image data. Aforesaid recording apparatus may be classified by the recording system into ink jet system, wire dot system, thermal system, laser beam system, etc.
The recording sheet used for recording apparatus may be, in addition to the ordinary sheet, a thick sheet such as postcard, envelope etc. or special sheet such as thin plastic sheet. Recording sheet is fed by manual sheet feeding or fed automatically and continuously by automatic sheet feeding apparatus.
Said automatic sheet feeding apparatus may be a built-in type which is built into the recording apparatus, or external type which is mounted on the recording apparatus, and the present invention relates to the recording equipment on which the external automatic sheet feeding apparatus is mounted.
For the recording apparatus, a horizontal type apparatus is generally used and a sheet inserting hole and sheet discharge hole are provided on the upper surface of the apparatus, and it is so constructed that recording is executed while delivering the sheet along the recording sheet transporting route which is formed roughly in U-shape in the recording apparatus.
However, in the case of the conventional system wherein an automatic sheet feeding apparatus is mounted on the horizontal recording apparatus, the automatic sheet feeding apparatus is fixed on the upper surface of the said recording apparatus, so that the sheet is automatically fed at the aforesaid sheet inserting hole of the recording apparatus, and the automatic sheet feeding apparatus is fixed on the recording apparatus as the latter is horizontally set and therefore considerable space is necessary for its installation, thus presenting the problem of space efficiency.
Besides, the recording sheet transporting route is U-shaped and it is practically impossible to provide the transporting route linearly, thus presenting problems such as that when a recording sheet with rigidity such as postcard is printed, a smooth sheet delivery is impossible.
In the case of aforesaid conventional recording apparatus, recorded sheets are discharged upward from the sheet discharge port or hole and they are piled up on the stacker almost in upright posture and therefore the sheet being discharged (ascending) contacts the surface of the sheet which has just been recorded and the recorded sheet is apt to be stained.
Especially, in the case of the ink jet recording apparatus wherein recording is made by applying a liquid on the sheet, certain time is required for fixing the ink and besides such ink jet system is frequently used for color printing wherein printing is overlapped and consequently staining of the recorded surface becomes sometimes excessive.
In order to solve this problem, such countermeasures have been taken as reinforcing ink fixing action or reducing discharge speed but such measures require the use of a large apparatus and accompanies increase of cost, decrease of throughput, etc. and it was not a conclusive solution.
When an external automatic sheet feeding apparatus is mounted on the recording apparatus, a system to drive the sheet feeding roller utilizing the driving force of the recording sheet transporting system (driving force to drive sheet feeding roller) has been employed and at the joint of said two systems is the section where drive gear and driven gear mesh with each other.
However with the conventional construction, automatic sheet feeding apparatus is generally mounted on the recording apparatus, the flat sections formed by the two casings are brought in contact to clamp them, and therefore many parts exist at the relative position between the driving gear supported by the frame member of the recording apparatus main body (usually via a bearing member) and the driven gear axially supported at the automatic sheet feeding apparatus and due to the accumulation of error related to such system, it has been difficult to set the shaft to shaft distance with high precision.
Besides, since the casing part is brought in pressure-contact with the apparatus, a deflection may be produced at the casing during use due to vibration or other external force, thus the shaft to shaft distance of the gears varies and jumping of teeth of the gear occurs resulting in an inaccurate sheet feeding action.
Besides, with the conventional construction wherein an automatic sheet feeding apparatus is mounted on the horizontally set recording apparatus, the automatic sheet feeding apparatus is set at the upper surface and fixed at certain posture so that the sheet is fed automatically at the sheet inserting hole, and therefore it not only requires large installation space at the time of use but also the similarly large installation space even for storage of the apparatus, since the apparatus must be held in the same posture even during storage. Thus it presents the technical problem of low space efficiency.